En fait, ce n'est pas si dur que ça:
Producing Graphical Output
To display the solution of the previous example graphically, use the command
plot (t, x)
If you are using the X Window System, Octave will automatically create a separate window to display the plot. If you are using a terminal that supports some other graphics commands, you will need to tell Octave what kind of terminal you have. Type the command
gset term
to see a list of the supported terminal types. Octave uses gnuplot to display graphics, and can display graphics on any terminal that is supported by gnuplot.
To capture the output of the plot command in a file rather than sending the output directly to your terminal, you can use a set of commands like this
gset term postscript
gset output "foo.ps"
replot
This will work for other types of output devices as well. Octave's gset command is really just piped to the gnuplot subprocess, so that once you have a plot on the screen that you like, you should be able to do something like this to create an output file suitable for your graphics printer.
Or, you can eliminate the intermediate file by using commands like this
gset term postscript
gset output "|lpr -Pname_of_your_graphics_printer"
replot
Donc ça marche tout seul avec X11.